|Publication number||US4360883 A|
|Application number||US 06/175,697|
|Publication date||Nov 23, 1982|
|Filing date||Aug 6, 1980|
|Priority date||Mar 22, 1978|
|Also published as||DE2911123A1|
|Publication number||06175697, 175697, US 4360883 A, US 4360883A, US-A-4360883, US4360883 A, US4360883A|
|Inventors||Koichi Ejiri, Morisumi Kurose, Seiji Hayakawa|
|Original Assignee||Ricoh Co., Ltd.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Non-Patent Citations (2), Referenced by (27), Classifications (9), Legal Events (1)|
|External Links: USPTO, USPTO Assignment, Espacenet|
T1 =S1 +S2
T2 =S1 +S4
T3 =S2 +S5
T4 =S4 +S5
This is a continuation, of application Ser. No. 020,055, filed on Mar. 13, 1979, now abandoned.
This invention relates to a method of restoring a picture cell by estimation with high density in a copying machine.
FIG. 1 shows a picture consisting of nine equal square picture cells obtained by sampling a copying original.
Heretofore, in restoring the central picture cell X by estimation, the estimation is carried out by approximation over linear polynominals including the density data of the eight picture elements A, B, C, D, E, F, G and H surrounding the central picture cell X. The estimation coefficients of the picture cells B, D, E and G are about 0.5, and those of the picture cells A, C, F and H are about -0.25 for Japanese and European languages if they are of a sentence pattern. Therefore, in estimating the central picture element X, there is no substantially great difference in picture quality between the case where all of the picture cells A through H are utilized and the case where only four picture cells B, D, E and G are utilized. This is due to the mutual relations between the central picture cell X and the surrounding picture cells A through H. In other words, the estimation is greatly affected by the picture cells B, G, D and E which are positioned above, below, at the left-hand side and at the right-hand side of the central picture cell X, and is not so affected by the remaining picture cells A, C, F and H.
In view of the foregoing, an object of this invention is to provide a method of restoring a picture cell by estimation in which the number of picture cells utilized for the estimation is reduced, which contributes to simplification of the algorithm of restoring the picture cell by estimation.
Another object of the invention is to provide a method of restoring a picture cell by estimation by which the construction of a copying machine is simplified and the manufacturing cost thereof can be reduced.
The novel features which are considered characteristic of this invention are set forth in the appended claims. This invention itself, however, as well as other objects and advantages thereof will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.
In the accompanying drawings:
FIG. 1 is an explanatory diagram showing picture cells forming a picture sampled and for a description of a conventional method, which has been already referred to;
FIG. 2 is an explanatory diagram for a description of a method of restoring a picture cell by estimation according to the invention;
FIG. 3 is a flow chart showing algorithm according to the invention; and
FIG. 4 is a block diagram showing a picture cell restoring device for realizing the flow shown in FIG. 3.
FIG. 2 shows five picture cells out of nine picture cells forming a picture, which are obtained by sampling a copying original. The five picture cells are utilized in a method of restoring a picture cell by estimation according to this invention. The picture cell to be restored is positioned at the center of the five cells and is designated by reference character S3.
The picture cell S3 is divided into four equal squares which are referred to as sub-cells O1, O2, O3 and O4, respectively. The output conditions of these sub-cells O1 through O4 are determined from the density data of the remaining picture cells S1, S5, S2 and S4 which are positioned above, below, on the left-hand side and on the right-hand side of the central picture cell S3, respectively, to restore the central picture cell S3 by estimation.
The algorithm in restoring the central picture cell by estimation is as follows:
(1) The following equations are calculated: ##EQU1## where S1, S2, S4 and S5 are the densities of the respective picture cells, and each of the values S1, S2, S4 and S5 is one (1) when the respective picture cell is black, zero (0) when white, and a value between one and zero when grey.
(2) Then, the central picture cell S3 is subjected to quinary quantization. If the resultant value is represented by S3 q, then S3 q =1/5, 2/5, 3/5, 4/5, 5/5. The following determinations are effected:
When the quantized picture cell S3 q =1/5, ##EQU2## (3) When 2/5≦S3 q ≦4/5, the data T1, T2, T3 and T4 calculated as above are arranged in the order of magnitude, and the data thus arranged will be represented by Ti, Tj, Tk and Tl, respectively.
(4) Then, with Oi - =1 and Oj =Ok =Ol - =0, 1/5 is subtracted from S3 q.
(5) As a result of this subtraction, if S3 q is smaller than 1/5, then the algorithm is completed; and if S3 q is larger than 1/5, then the algorithm is advanced to the next step.
(6) With Oj - =1, 1/5 is subtracted from S3 q.
(7) As a result of this subtraction, if S3 q is smaller than 1/5, then the algorithm is completed; and if S3 q is larger than 1/5, then the algorithm is advanced to the next step.
(8) Ok =1
The flow of the above-described algorithms (1) through (9) is as indicated in FIG. 3. These algorithms are carried out for the entire surface of an original to be copied, but are not effected for the end portions of the original.
FIG. 4 is a block diagram showing a picture cell restoring device for realizing the flow indicated in FIG. 3. The picture cell restoring device comprises: an address counter 1 for counting the absolute address of the central picture cell S3 (the provision of the address counter 1 being not always necessary); an address specifying section 2 operating to specify the addresses of the picture cells S1 through S5 according to data from the address counter 1; a memory 3 for temporarily storing data read out; a level decoder for deciding the density levels of the picture cells S1 through S5 ; an address counter signal converter circuit 5 which controls the algorithms described above according to data from the address counter 1 and suspends the logical decision at the end portions of an original to be copied; and a logical decision circuit 6 which is operated when the density level of the picture cell S3 is 2/5, 3/5 or 4/5.
The picture cell restoring device further comprises: a black picture cell generating circuit 7; and a white picture cell generating circuit 8. When the density level of the picture cell S3 is 1/5, the entire picture cell (O1 -O4) is estimated as white, and when 5/5, black.
As is apparent from the above description, according to the invention, it is unnecessary to use all of the eight picture cells to restore the central picture cell unlike the conventional method. That is, the aimed picture cell can be restored by estimation only with four picture cells above, below, right and, left readily when compared with the eight-picture-cell method. This will contribute to simplification of the copying machine and to reduction in the manufacturing cost thereof.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2962550 *||Feb 6, 1957||Nov 29, 1960||Time Inc||Resolution restorer system|
|US3999047 *||Nov 25, 1974||Dec 21, 1976||Green James E||Method and apparatus utilizing color algebra for analyzing scene regions|
|US4131883 *||Jan 13, 1977||Dec 26, 1978||Asea Aktiebolag||Character generator|
|US4150400 *||Mar 31, 1977||Apr 17, 1979||International Business Machines Corporation||Methods of a coarse-scan/fine-print character reproduction with compression|
|1||*||Appel et al.; "Automatic Filling of Bounded Areas in a Raster Display"; IBM Tech. Discl. Bulletin; vol. 21, No. 3, Aug. 1978; pp. 1300-1303.|
|2||*||Stucki; "Optimal Digital Halftone Pattern Generation Method"; IBM Tech. Discl. Bulletin; vol. 17, No. 9, Feb. 1975; pp. 2779-2780.|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US4517607 *||Oct 29, 1982||May 14, 1985||Ricoh Company, Ltd.||Method of and apparatus for compensating image in image reproduction system|
|US4590558 *||Dec 30, 1981||May 20, 1986||General Electric Company||Method and apparatus for removing objects from CT images|
|US4630307 *||Sep 10, 1984||Dec 16, 1986||Eastman Kodak Company||Signal processing method and apparatus for sampled image signals|
|US4680720 *||Oct 15, 1984||Jul 14, 1987||Kabushiki Kaisha Toshiba||Dot interpolation control system|
|US4720745 *||Jun 22, 1983||Jan 19, 1988||Digivision, Inc.||Method and apparatus for enhancing video displays|
|US4771471 *||Dec 30, 1985||Sep 13, 1988||Dainippon Screen Mfg. Co., Ltd.||Smoothing method for binary-coded image data and apparatus therefor|
|US4791678 *||Feb 22, 1988||Dec 13, 1988||Fujitsu Limited||Image processing system|
|US4806759 *||Oct 9, 1986||Feb 21, 1989||Fuji Photo Film Co., Ltd.||Method of adjusting radiation image read-out conditions|
|US4853752 *||Jan 27, 1988||Aug 1, 1989||Canon Kabushiki Kaisha||Image processing method|
|US4853794 *||Nov 23, 1987||Aug 1, 1989||Sakata Inkusu Kabushikikaisha||Method and image processing system for reconstruction of an image|
|US4870497 *||Jan 22, 1988||Sep 26, 1989||American Telephone And Telegraph Company||Progressive transmission of high resolution two-tone facsimile images|
|US4873577 *||Jan 22, 1988||Oct 10, 1989||American Telephone And Telegraph Company||Edge decomposition for the transmission of high resolution facsimile images|
|US4907152 *||Dec 5, 1988||Mar 6, 1990||The Boeing Company||Method of improving CT resolution|
|US4920267 *||Apr 11, 1988||Apr 24, 1990||Fuji Photo Film Co., Ltd.||Method of detecting noise in image signals|
|US4979049 *||Jun 1, 1989||Dec 18, 1990||At&T Bell Laboratories||Efficient encoding/decoding in the decomposition and recomposition of a high resolution image utilizing its low resolution replica|
|US5031053 *||Jun 1, 1989||Jul 9, 1991||At&T Bell Laboratories||Efficient encoding/decoding in the decomposition and recomposition of a high resolution image utilizing pixel clusters|
|US5068914 *||Aug 29, 1988||Nov 26, 1991||Eastman Kodak Company||Apparatus for reducing artifacts in error diffused images|
|US5404233 *||Aug 7, 1991||Apr 4, 1995||Kyocera Corporation||Method for smoothing image|
|US5410614 *||Oct 22, 1993||Apr 25, 1995||Industrial Technology Research Institute||Run-based method for smoothing handwritten Chinese characters|
|US5717782 *||Nov 14, 1994||Feb 10, 1998||Wyko Corporation||Method and apparatus for restoring digitized video pictures generated by an optical surface-height profiler|
|US5796878 *||Dec 13, 1994||Aug 18, 1998||Canon Kabushiki Kaisha||Image interpolating circuit|
|US5815605 *||May 17, 1995||Sep 29, 1998||Ricoh Company, Ltd.||Image processing system and method|
|US6021230 *||Nov 26, 1997||Feb 1, 2000||Samsung Electronics Co., Ltd.||Interpolation method for binary image|
|US6055336 *||Nov 18, 1996||Apr 25, 2000||Canon Kabushiki Kaisha||Image processing system which converts multi-value image data into binary image data|
|US6545686||Feb 2, 1999||Apr 8, 2003||Oak Technology, Inc.||Cache memory and method for use in generating computer graphics texture|
|US20090059255 *||Aug 28, 2008||Mar 5, 2009||Toshio Ohide||Image processing apparatus, image forming apparatus, and image processing method|
|USRE37792 *||Jul 31, 2000||Jul 16, 2002||Samsung Electronics Co., Ltd.||Interpolation method for binary image|
|U.S. Classification||382/254, 358/447, 348/625|
|International Classification||G06T3/40, H04N1/387, G03B27/72, H04N1/417|
|Aug 17, 1982||AS||Assignment|
Owner name: RICOH CO., LTD. 3-6 NAKAMAGOME 1-CHOME, OHTA-KU, T
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:EJIRI, KOICHI;KUROSE, MORISUMI;HAYAKAWA, SEIJI;REEL/FRAME:004025/0357
Effective date: 19790305